In a continuously variable transmission (hereinafter, referred to as a “CVT with a sub-transmission mechanism”) including a combination of a continuously variable transmission mechanism (variator) and a sub-transmission mechanism, a shift range can be enlarged and fuel economy can be improved as compared with normal continuously variable transmissions.
In the case of shifting the sub-transmission mechanism in this CVT with the sub-transmission mechanism, it is possible to suppress a change of a through speed ratio, which is a speed ratio of the entire transmission, before and after the shift and suppress a shift shock by performing a synchronization shift for shifting a speed ratio of the variator in a direction opposite to a shifting direction of the sub-transmission mechanism (JP5-79554A).
A technology for providing a manual mode in a continuously variable transmission and controlling a speed ratio of the continuously variable transmission to a speed ratio corresponding to a gear position selected by a driver is known (JP2002-243031).